Code of Federal Regulations Title 26. Internal Revenue § 26.1.410(a)–9T Elapsed time (temporary)

(i) [Reserved]

(ii) For purposes of section 410(a)(1)(B)(i), a “2–year period of service” shall be deemed to be “2 years of service.”

(i) to (iii) [Reserved]

(iv) For purposes of determining an employee's nonforfeitable percentage of accrued benefits derived from employer contributions, a plan, after calculating an employee's period of service in the manner prescribed in this paragraph, may disregard any remaining less than whole year, 12–month or 365–day period of service. Thus, for example, if a plan provides for the statutory three to seven year graded vesting, an employee with a period (or periods) of service which yields 3 whole year periods of service and an additional 321–day period of service is twenty percent vested in his or her employer-derived accrued benefits (based solely on the 3 whole year periods of service).